STRESS DISTRIBUTIONS ON THE RAKE FACE DURING ORTHOGONAL MACHINING

The authors describe the design, calibration and testing of a split tool dynamometer that has been developed to allow the estimation of rake face stress in a true orthogonal machining process. The device is unique, in that force measurements can be made on the front and rear portions of the cutting tool simultaneously. The normal and shear stress distributions over the rake face of the tool have been calculated based upon cutting tests using AISI C1045 steel, SAE CA360 free cutting brass and AISI 304 stainless steel discs as the work material at a cutting speed of 130 m/min. The experiments also gave insight into the chip sticking length and comparison with scanning electron microscope (SEM) images of the rake face revealed that the dynamometer indeed provides an accurate assessment of the overall chip contact length along the rake face.